Overview
This document contains information on:
General
Location
Function
General
The exhaust gas recirculation cooler cools down the branched off exhaust gases from a temperature of approx. 650 °C to a temperature of approx. 170 °C.
The exhaust gas recirculation cooler reduces the temperature of the recirculated exhaust gas. The exhaust gas recirculation rate is thus higher and the nitrogen oxide emissions lower.
Lowering of the temperature produces a higher density of the exhaust gases, without increasing the number of particles.
Location
The exhaust gas recirculation cooler is located downstream of the exhaust manifold within the exhaust gas recirculation unit.
Function
The exhaust gas recirculation cooler consists of a oblong box-shaped housing in which there is an exhaust-gas chamber with cooling ducts passing through it.
Coolant flows around the exhaust gas recirculation cooler housing that is made from stainless steel.
The exhaust gas coming from the exhaust manifold flows through the exhaust intake into the exhaust-gas chamber. The exhaust gas flows through this and thus reaches the exhaust outlet in the direction of the charge air pipe, where it is supplied together with the supercharged fresh air to the combustion.
Coolant permanently flows thought the ducts inside the exhaust gas recirculation cooler from the engine coolant circuit. The coolant collecting rail then returns the coolant via the coolant collecting rail to the engine. The heat transfer between the cooling ducts and the exhaust-gas chamber cools down the exhaust gases.